Experimental study of plasma fluxes in the shadow of a scoop limiter on T-10

Abstract

Investigation of plasma fluxes measured by Langmuir probes on both sides of the T-10 scoop limiter shows the existence of large asymmetry, depending on discharge parameters. Two mechanisms can be responsible for such asymmetry. At low density, rotation of the plasma periphery in the direction of the plasma current causes the asymmetry. At high density it arises due to the preferential escape to the external side of the torus and its further spread along the magnetic field lines. The dependence of the neutral gas pressure under the limiter on the plasma influx to the channels was not linear. A pressure up to 30 mTorr has been observed.